Reed root is a kind of traditional Chinese medicine, with the efficacy of clearing heat and generating fluids, stopping vomiting and removing vexation. It is often used in fever, thirst, thirst, dry tongue, or gastric fever, vomiting, lung fever, cough, phlegm, dry mouth, and external wind-heat cough. About rehmannia, there is a folk legend. Legend has it that once upon a time there was a poor family surnamed Tian, one year at the turn of fall and winter, due to the child suffered from wind-cold, burned red, sleeping, the poor people rushed to the town's pharmacy to buy medicine. The poor man rushed to the pharmacy to buy medicine. The owner of the pharmacy, nicknamed Knife Black Heart, said slowly to the poor man, "To reduce the fever, you need to take antelope horn; without antelope horn, the fever will not go away." The poor man hurriedly asked, "How much does that antelope horn cost?" Knife Blackheart said, "To reduce the fever you need five cents of antelope horn, a precious herb, one point or two, five cents and five taels of silver." The poor people where there is so much silver, so to knife black heart begged can not less money. Knife black heart put a sinking face, said: "poor man, can not afford to buy medicine, do not come, I still do not want to sell you!" Poor people heard very angry, but there is no way, no choice but to bear the anger out of the drugstore. As soon as the poor man stepped out of the door of the pharmacy, he bumped into a beggar. The beggar sympathetically said to the poor man: "fever does not have to eat antelope horn can not, I teach you a method, do not spend a penny, you can reduce the child's fever." The poor man was very grateful, and hurriedly asked, "Good master, what method?" The caller said: "you quickly to the pond to dig some reeds, wash with water, give the child decoction into a soup to drink, the fever will naturally subside," the poor man listened to the pond outside the village dug some fresh reeds, wash with water to remove the mud and sand on the root, cut into half an inch long, decocted into a soup for the child to pour down. Sure enough, after three doses, the child's fever subsided and healed. Since then, people in the village know that rehmannia can solve the fever, is a fever reducer, who has a high fever patient, will go to dig some rehmannia, no longer go to the pharmacy to seek the knife black heart, rehmannia has become a flavor of the folk medicine that does not cost the fever.